I am doing research on what classes college students have. 
Specifically Im trying to figure out how many students will take the
subjects of math, physics, chemistry, biology, other sciences,
statistics in their college tenure.  For instance a math major will
definitely take those courses but a social science may or may not take
a math course based on their preference and the general education
requirements of that school.

I have found numbers from the UCLA/HERI "The American Freshman
National Norms For Fall 2004 Report" which gave me the number of 
expecting to take different majors.  I also found the students which
got diplomas in groups of majors via  US Department of Education,
National Center for Educational Statistics, Higher Education General
Information Survey (HEGIS).  For instance mentioned how many
Engineering graduates there were in the US but didnt mention the
number of mechanical or civil etc.

Can you help me figure out how many students took math, science, stat
and engineering courses within a year or how many have to take them
within their college tenure?  If you found some general numbers of
major or subject or class internationally that would be helpful though
not required.

These are all undergraduate college courses I am referring to.  (some
grad students have to take undergraduate math as a pre req)